GMC duramax diesel 2016 Supplement Manual page 96

American Petroleum Institute (API)
symbol
This doughnut-shaped logo
(symbol) is used on most oil
containers to help you select the
correct oil. It means that the oil has
been certified by the American
Petroleum Institute.
Look for this on the oil container,
and use only those oils that display
this logo.
Caution
Use only engine oils that have the
designation CJ-4 for the diesel
engine. Failure to use the
recommended oil can damage the
DPF and result in engine damage
not covered by the vehicle
warranty.
Viscosity Grade
Use SAE 15W-40 viscosity grade
engine oil.
When it is very cold, below 18 °C
(0 °F), use SAE 5W-40 to improve
cold starting. These numbers on the
oil container show its viscosity,
or thickness.
When selecting an oil of the
appropriate viscosity grade, always
select an oil of the correct
specification. See Specification
earlier in this section.
Vehicle Care
Engine Oil Additives/Engine Oil
Flushes API
Do not add anything to the oil. The
recommended oils with the API
service symbol are all that is
needed for good performance and
engine protection.
Engine oil system flushes are not
recommended and could cause
engine damage not covered by the
vehicle warranty.
What to Do with Used Oil
Used engine oil contains certain
elements that can be unhealthy for
your skin and could even cause
cancer. Do not let used oil stay on
your skin for very long. Clean your
skin and nails with soap and water,
or a good hand cleaner. Wash or
properly dispose of clothing or rags
containing used engine oil. See the
manufacturer's warnings about the
use and disposal of oil products.
Used oil can be a threat to the
environment. If you change your
own oil, be sure to drain all the oil
from the filter before disposal. Never
dispose of oil by putting it in the
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